Transfer systems of the type cited are for example described in detail in the book: Schuler, Handbuch der Umformtechnik, Schuler AG, Springer Verlag, Heidelberg, 1996, see in particular pages 230 to 242.
JP-A-2005014071 discloses a transfer system in which a motor drives a toothed wheel, by means of which a lifting and at the same time a lateral movement of a plate is performed.
FIG. 1 shows a three-dimensional view of a transfer system of the prior art, which is as a whole designated 10. The transfer system 10 is intended to transport workpieces between the tools of a press, which are not shown in the figure, and may be between a few meters and almost 100 m in length. To mount the transfer system 10 on the presses, an assembly structure 12 is arranged at one end of the transfer system, and an assembly structure 14 is arranged at the other end of the transfer system. At the heart of the transfer system are two transport beams 16. The transport beams 16 extend over the entire length of the transfer system 10. A movement of the transport beams 16 is effected by means of three different electric motors 18. It would basically be sufficient if three electric motors 18 were arranged on one side of the transfer system, but in the present instance, three electric motors 18 are in each case arranged on each side of the transfer system. One of the electric motors 18 on each side is responsible for a relative movement of the transport beams 16 towards each other corresponding to the arrow 20. By means of this relative movement 20, the transport beams can clamp a workpiece in place between them. A second of the electric motors 18 is responsible for a translatory movement along the longitudinal extension of the transport beams 16, see arrow 22. A third of the electric motors 18 on each side of the transfer system 10 is responsible for a lifting movement, see arrow 24.
The need to provide an electric motor in each case for each type of motion (arrows 20, 22 or 24), where the number of electric motors must even be doubled so that an electric motor effects the movement on both sides according to the type of motion, is a costly factor.